Studies are underway to quantitate right heart function in infants, children, and adults with heart disease. Methodology is being developed to calculate right and left atrial volumes and right and left ventricular volumes from biplane cineangiocardiograms. In addition, video imaging is being developed to provide rapid volume calculations directly from video data. Parallel studies are also underway on the physiology and pharmacology of developing right heart muscle in kittens and rabbits.